More recently, a small study in healthy Yucatan mini pigs revealed that low-dose AAV9-BAG3 gene transfer by catheter-guided retrograde coronary sinus infusion resulted in widespread myocardial transduction [74], pointing to a potentially viable approach to efficiently deliver BAG3 transgene in the setting of cardiomyopathy and HF. The gene discussed is BAG3; the disease is hydrops fetalis.